Cooper (Chapman) Lake Water Level
Texas · updated daily from the Texas Water Development Board
80.2% full
Cooper (Chapman) Lake is below full at 437.01 ft and falling (-0.31 ft in the last 7 days).
2.99 ft below full pool of 440.00 ft · change since yesterday -0.04 ft
Reading as of 2026-08-15 · higher than 35% of August readings on record
Where Cooper (Chapman) Lake sits historically
Today's level compared with every reading in our 25.9-year record for this lake.
Since yesterday
-0.04 ft
7-day change
-0.31 ft
30-day change
-1.18 ft
1-year change
-2.20 ft
Full pool
440.0 ft
Last 30 days
Last 12 months
Full history (25.9 years)
Cooper (Chapman) Lake records and averages
| Current level | 437.01 ft |
|---|---|
| Percent full | 80.2% |
| Storage | 243,255 acre-feet |
| Record high | 448.51 ft (2018-03-02) |
| Record low | 422.02 ft (2006-12-28) |
| Average of all readings | 436.76 ft |
| Data span | 25.9 years (9,320 readings) |
Frequently asked questions
Is Cooper (Chapman) Lake full right now?
Cooper (Chapman) Lake is at 80.2% of conservation capacity as of 2026-08-15, which we classify as below full.Over the past 30 days the level has fallen 1.18 ft.
What is the water level at Cooper (Chapman) Lake today?
The most recent reading is 437.01 ft (2026-08-15), sourced from the Texas Water Development Board. Readings on this page refresh automatically as the agency publishes new data.
What is the highest Cooper (Chapman) Lake has ever been?
The highest level in our records is 448.51 ft on 2018-03-02. The lowest is 422.02 ft on 2006-12-28. Our record covers about 25.9 years of readings.
Is Cooper (Chapman) Lake low for this time of year?
Compared with every August in our records, the current level is higher than 35% of them — below full. Seasonal comparison matters more than the raw number, because most reservoirs draw down predictably through late summer and refill over winter and spring.
Why is Cooper (Chapman) Lake low right now?
Reservoir levels move for four main reasons: rainfall and runoff into the basin, releases through the dam for downstream water supply, power generation or flood control, evaporation during hot months, and seasonal drawdown schedules set by the operating agency. Cooper (Chapman) Lake has fallen 1.18 ft over the past 30 days. For the operational reason on any given week, check the Texas Water Development Board directly.
How much has Cooper (Chapman) Lake changed over the past year?
The level is -2.20 ft compared with this date last year (437.01 ft today). The full-history chart above covers 25.9 years, with a record high of 448.51 ft and a record low of 422.02 ft.
Nearby lakes in Texas
Source: the Texas Water Development Board. Readings are provisional and subject to revision by the publishing agency. All Texas lake levels.